The present invention relates to an imaging system for in vivo examinations of tissues, and particularly to a confocal imaging system operative upon the tissue of a patient body part or animal subject which mechanically stabilizes the tissue to minimize instability in confocal images of the tissue. This invention is especially suitable for providing an instrument or attachment for pathological applications.
This application is related to U.S. application Ser. No. 08/683,607, filed on Jul. 15, 1996, and entitled Three-Dimensional Scanning Confocal Laser Microscope, now U.S. Pat. No. 5,880,880.
Systems have been proposed for confocal scanning of skin, such as described in an article by Rajadhyaksha et al., entitled xe2x80x9cIn vivo Confocal Scanning Laser Microscopy of Human Skin:
Melanin provides strong contrast,xe2x80x9d The Journal of Investigative Dermatology, Volume 104, No. 6, June 1995, pages 1-7, and also Rajadhyaksha et al., entitled xe2x80x9cConfocal laser microscope images tissue in vivo,xe2x80x9d Laser Focus World, February 1997, page 119-127. These systems have confocal optics which direct light to the patient""s skin tissue and image the returned reflected light. Such optics has a limited field of view of the patient""s skin tissue, which for example may cover a tissue area less than one millimeter wide. One problem with these systems is that motion of the patient during confocal imaging can cause the tissue area being imaged to move relative to the system""s confocal optics, shifting the field of view of the tissue area with respect to the optics. Consequently, confocal images from such systems may appear unstable to the viewing physician, making it difficult for the physician to observe dermal structures of interest. Even slight motion of the patient""s skin tissue, such as due to involuntary muscle movement in adjacent tissue or from a circulatory pulse, can cause dermal structures of a confocal image to appear to move in and out of the imaged tissue area. The confocal optics may also image other types of patient tissue in addition to dermal tissues, for example, oral tissue of the tongue or lip, but motion of such tissue can still cause instability in confocal images of tissue structures.
Accordingly, it is the principal object of the present invention to provide an improved system for confocal imaging of tissue of a patient which minimizes instability in confocal images by reducing the relative motion of the tissue with respect to the confocal imaging optics of the system.
It is another object of the present invention to provide an improved system for confocal imaging having a clamping apparatus which mechanically stabilizes the tissue to a confocal imaging system within the improved system.
Briefly described, the present invention embodies a system having a clamping apparatus with first and second members, which are spaced apart from each other. An attachment mechanism is connected to the first member for attaching the apparatus to a confocal imaging system. The attachment mechanism has a surface facing the tissue to be examined. Opposing this surface is a third member which is connected to the second member. A clamping mechanism includes the first and second members for clamping the tissue between the surface of the attachment mechanism and the surface of the third member. A window is provided in the surface of the attachment mechanism for presenting the clamped tissue to the confocal imaging system.
The clamping mechanism may include a turn screw threaded through the first and second members, or a pneumatic system, for clamping the apparatus to the tissue. An optional suction mechanism may be used to assist in clamping the tissue to the attachment mechanism.